// 所有类型都可以分配给 unkonw
let notSure: unknown = 4
notSure = 'string'
notSure = [1, 2, 3]

// 只能赋值给 unknown 和 any
let nameString = 'well'
// nameString = notSure // error
let notSureA: unknown = 2
notSure = notSureA
let anyA: any = 2
anyA = notSure
